<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Title</title>
    <link rel="stylesheet" href="./css/12.css">
    <script src="./js/12.js"></script>
</head>
<body>
    <select name="arg" id="sel">
        <option value="">默认选项</option>
    </select>
    <br><br>
    <input type="button" value="打印选中的option的value值" onclick="printSelectOptionValue()">
    <input type="button" value="切换选中项" onclick="changeSelectOption()">
    <br><br>
    <input type="button" value="打印选中的option" onclick="printSelectOption()">
    <hr>
    <table id="table">
        <tbody>
            <tr>
                <td>行1列1</td>
                <td>行1列2</td>
                <td>行1列3</td>
                <td>行1列4</td>
                <td>行1列5</td>
            </tr>
            <tr>
                <td>行2列1</td>
                <td>行2列2</td>
                <td>行2列3</td>
                <td>行2列4</td>
                <td>行2列5</td>
            </tr>
        </tbody>
    </table>
    <br>
    <input type="button" value="打印表格第二行第三列的内容" onclick="printCellContent()">
</body>
</html>